Directional apparatus



.lune 25, 1935 W. MOSER DIRECTIONAL APPARATUS Filed May 5l, 1930`INVENTOR WILHELM MOSER BY ,/'lv

/z/mH/i/ ATTORNEY Patented June 25,1935 290.5978 ,i

` t. amavas'f l@ nrREC'rIoNALarrRA'rUs Wilhelm Moser, ,Berlin, Germany,assigner to TelefunkenmGesellschaft `iiir Dralitlose Telegraphie m. b.H., Berlin, Germany, a corporation' oi'fGermany Y. u i. i j

Application May 31, 1930, serial No. 457,830 i In Germany August 31,1929 2 claims. (ci: 25o-11)' i y `It has been y'ascertained thathorizontal anthe twin contacte of arelayf However, this form tennaeoffer certain advantages over vertical anof construction still involvesthe demerit that the tennae both for the transmission and the recep-`rate of speedat which the changes occur in .the tion of shortl waves.This condition holds good yconnecticns of the antennae d1 and d2 islimlted 5 particularly for directional antenna, most espeby the relayspeed. An embodiment whichpon- 5 cially when a marked beamorbunchingaction is 4 stitutes anv improvement in this respect is illusto'be insured horizontally and vertically." The4 trated in Fig. 3` in whichalternate detuning by essence and basic element of ahorizontal antennathe aid of the gear-wheel f is insured by virtue is the horizontaldipole, and the latter itself, as of the changes `in capacities g1 andg2 brought l0 `known ,from theory, possesses a directive action. `aboutby the rotation ofthe said gear-wheel. In 10 Hence, ahorizontal dipoleor an antenna consistthis manner, circuit-change rates are obtained 4ing of horizontal dipoles is not readily suited for being equal to thecircumferential speed times ybroadcast transmitters in which the mainpoint numberof teeth. Arrangements in this scheme aimed at is `to insureequally or fairly good radiare sochosen that the capacity g1 must haveits 1 5 Y ationin all directions or at least in several direc-V crestvalue when g2 has its minimum value. 15

tions. f-Hence, if with horizontal antennae insur- Another embodiment isshown in Fig.' 4 in ing a more or less `marked beam action, places whichthe energy leads h1 and h2 are connected located also outsidewthedirectional `diagram are with thecoupling coils ci and c2, said leads inturn to be reached, then a plurality` of antennae must being brought tothe two directive antennae being,

be alternatively used. In'actual operation such for instance, of what isknown as the Christ 20 `alternate use may be found a. handicap under mastree type, wherein the sets of radiators i1 certain circumstances. Thiswould be true, for and i2 are arranged in a vertical plane, the planesinstance, of transmissions or signals of a broadbeing at right angleswith respect to each other cast nature which must be received.l andtransso that each set is directive in a different direction.mitted-simultaneouslyin several directions. Now, In parallel relation tothe coupler coils ci and c2 25 in cases of this kind thepresentvdisclosure indiis a series connection of capacities Ici and k2 and catesuseful ways and'rneans obviating thesaid inductances Z1 and Z2 which aretraversed by difficulty bythe combination of a plurality of diradiofrequency currents. The said inductances rective antennae 'acting invarious directions and are of the iron-cored type, the iron core beingwhich are operated `alternately at a Sulliciently saturated alternatelyby auxiliary windings 2 and 30 rectional `diagrams ofboth antenn will beemshort-circuit'in parallel to the coupling coils c1 y rapid or shortsequence. By the aid of such an d at an audio frequency rhythm from theaudio arrangement two directive antennae mounted at frequency sourcethrough the leads mi and m2.` In the same place but in diiferent rmannermay be the presence of saturation of the iron-cores Z1 and so combinedthat the directions given by the dik1 and Z2, k2 are in series resonanceand act as a braced by 011e transmitter 0I' IeCeiVer. and c2. lI-Ience,at the instants when the audio A more complete understanding will `behad of frequency current is one of the auxiliary windings the inventionfromthe following specification and 2 or ll saturates the core of saidwinding the setherefrom when read with `the attached drawing riescircuit associated therewith will be series ill WhCh Fig. 1 SHOWStheharacteristic curve of resonant to the radio frequency current from a40 a pair of directional `aerials-operated in accordand willshort-circuit c1 or c2 and the correance With my invention; spondingantenna will not radiate energy. The

Fig. 2 showsanembodiment of the invention; manner in which alternatesaturation may be while brought about will be evident to the man trainedFigs. 3 to 5 inclusive show modications of the in the-art and need notbe explained here. 45 arrangement 0f Fg- 2; Fig. 5 shows an arrangementin which radio In what follows reference is made to only two` frequencyamplifiers m and 11.2 are associated with antennae, though it will beunderstood that what the coupling coils ci and c2, said ampliers in isset forth may analogously be applied` to any turn -feeding ampliiiedenergymto the antennae 111 desired number `of antenna. and i2. Theamplifier stages 11a-and n2 include 50 Fig. 2 illustrates the simplestarrangement. a transmitter tubes which are alternately rendered denotesa transmitter whose intermediate-circuit operative and inoperative bychanging the Value coil b works uponthe two coupling coils ci and zzV ofthe potential applied to the grid lelectrodes of of antennae d1 Vand d2,respectively. 4The antennaA the tubes. It is well known that'such analter-V r leads are alternately grounded by the agency of nate change inoperation can be produced at 05 ing problem of a transmitter.

As illustrated in Figure 5, the control grids of tubes n1 and n2aresupplied With equal direct current potentials from source Il)connected, as shown, -With the midpoint ofthe secondary Winding rof van-audio frequency transformer l2. The primary Winding of l2 is energizedby audio frequency currents. In this manner potentials op;- posite insign are applied alternatelywtothecontrol grids of tubes m and n2.superposed on the steady direct -,current po.tential change at an audiofrequency vrate the :operative- Aness of tubes n1 and n2 andthereforechange at These potentials said aerial systems, a single high frequencygenerator, means for inductively coupling said generator to all of saidfeed circuits simultaneously, and means for detuning said feed circuitssuccessively at an audible frequency rate including, variable reactancesconnected in parallel with eachof saidrstnamedreactances, `and a sourceof `audio frequency oscillations coupled to said parallel reactances tovary the same successively. 2. In directional radio apparatus thecombina,- tiouoffaradiant energy generator, a plurality of independentdirective aerials each connected with a vfeed circuit including animpedance, coupling means-between each of said feed circuits and saidgenerator, a variable impedance in parallel with each vof said rstnamedimpedances, each vanetic circuits.

WILHELM MOSER.

